> The mozilla extension archive (.xpi), which is also a zip file, is
probably
> another useful model for what you're proposing.

Other models:

Yum in the Linux world.

From the PHP world, a PEAR package works in a similar way. it's a
tar.gz file packaged in a particular form, with an xml description
file. The pear installer knows how to open a properly formatted
PEAR package and put all the elements in the right place.

PEAR is great, because it allows anyone to set up their own PEAR
server, or "channel". So you don't have to get all your content from
one approved place.

To illustrate how a model like this could be used with xipf:

From your command line, your music gui app:

$ xipf channel-discover xipf.musicstore.walmart.com
$ xipf buy herbie_hancock^head_hunters

want to find out what albums are avialable from Herbie?

$ xipf list herbie_hancock

Again, the idea is that anyone can create their own channel, so if you
as an artist or indie lable want to sell direct, or compete with walmart:

$ xipf channel-discover xipf.musicstore.blacklovemusic.com
$ xipf list //gives you a list of available albums
$ xipf buy dr.oop^mad_hueman_disease